Individual people are usually the units of analysis. Best for a population too large to observe directly. Sometimes used improperly for example, political parties trying to acquire money for their political running campaigns. Questionnaire - contains questions to solicit information apprentie to analysis. Questions can be asked in a way that solicits a response of attitude. Likert scale, strongly agree, agree, strongly disagree, disagree. Open-ended questions - the respondent is asked to provide his or her own answer. Closed-ended questions - the respondent is asked to select an answer from a list. Provide greater uniformity of responses - more easily processed. Responses should be exhaustive - should include all possible responses. Answer categories should be mutually exclusive - you should only be able to answer one of the options. Avoid asking questions that delve deeply into topics that would be difficult for the correspondent to remember. Respondent may not be able to provide meaningful answers.